mod_rewrite and double slash issue

Question

I applied the following mod_rewrite rule in Apache2 to redirect from non www to www:

RewriteEngine On
RewriteCond %{HTTP_HOST} ^exa         


        

Answer 1

Fixed with:

RewriteEngine On
RewriteCond %{HTTP_HOST} ^mydomain\.com$ [NC]
RewriteRule ^(.*)$ http://www.mydomain.com$1 [R=301,L]

because $1 by default contains the index path /